Chemical contamination of the environment, particularly of soil and groundwater is currently a widespread problem that is prevalent in many parts of the industrialized world. Industrial pollution has contaminated millions of acres of soil and associated aquifers. Over the past several decades worldwide production, processing, storage, transportation and utilization of synthetic and naturally occurring chemical substances has led to the introduction of significant quantities of hazardous materials into the environment. Unintentional spillage of petroleum, industrial solvents, food and animal wastes and other substances has been caused, for example, by weathering, chemical corrosion and accidental damage to pipes, storage vessels, processing equipment, transportation vehicles, etc. Deliberate acts and carelessness have also contributed to the release of hazardous substances into the environment. The spillage of such materials has resulted in large numbers of polluted sites and enormous volumetric quantities of soil and groundwater which have been contaminated with hazardous substances. Soil contamination can cause extensive damage to the local ecosystem by accumulating in the tissue of animals and plants, and by causing death thereto and/or mutation to the progeny thereof. Such contamination can also present a serious health threat to humans and, in extreme cases, can render the contaminated area unsuitable for human habitation. In many cases, contaminated sites can pose a danger to adjacent property, such as by entrainment of hazardous substances by local groundwater flow, and local laws frequently mandate remediation prior to the sale or lease of property wherein the soil has been contaminated with hazardous materials.
Unfortunately, clean up of such contaminated sites and spills is extraordinarily difficult, and can be extremely labor intensive, costly and time consuming. Oil spills, especially involving water, are particularly troublesome to treat, as are oil producing well sites contaminated with crude oil. Existing cleaning technologies were often developed prior to the current environmentally-conscientious market. As such, environmentally harmful potentials such as runoff, toxicity, acid-base balances, and other downstream effects were seen in existing products. Technological improvements to existing cleaning products remained minor since large companies failed to recognize the growing market need for a suitable cleaning product applicable to soils, water, and hard surfaces.
The biological treatment or bioremediation of waste water, soil, oil spills, refinery waste, and other contaminants has been attempted in the past, but most technologies are fraught with complications and disadvantages. Some of these efforts have attempted to utilize bacteria, fungi or other microbes to biodegrade the contaminants, into more environmentally friendly materials, but most technologies have accompanying disadvantages and limitations.
Further, various microbial products were introduced with the concept of degrading the contaminants rather than simply transferring the problem from one site to another. To this end, enzymes were often added to existing products. However, since enzymes only perform within narrowly defined ranges of contaminants, the enzymes often ceased working once the contaminants were only partially degraded; leaving behind residue and secondary contaminants that could be as problematic as the original contaminant.
For example, European Patent No. 1352694, which is incorporated by reference herein in its entirety, discloses a method for the bioremediation of soils using a compost material derived from plant material, biological sludges, urban waste, animal manure, and combinations of bacteria, and/or molds in a liquid broth. This solution has some potential disadvantages such as difficult raw material handling and a final remediation agent that is limited to the treatment of soils. In addition the composting step may require a significant amount of time to produce the target remediation product, and the wide variation in the composting raw materials will likely result in broad variability in the bioremediation agent's final bioactivity and the composition of its final microbial flora.
U.S. Pat. No. 5,265,674 (“the '674 patent”) describes a method for the remediation of aquifers comprising injecting a liquid oil into the contaminated site, wherein the oil may further comprise microorganisms and nutrients. This method may be problematic if the oil itself does not degrade and subsequently accumulates in the aquifer. Further the method is somewhat limited in that it appears to be limited to the treatment of contaminated water sources. Finally, this method is applied as a liquid, which has spill hazards and complex, costly application methods. PCT Application WO 99/46210 and U.S. Patent Application Publication No. 2013/0023037 also describe composting methods, and both potentially suffer from the same disadvantages as the '674 patent.
Some methods for remediating soils that utilize in situ techniques such as aeration, venting and air sparging are generally limited to contaminants having a relatively high vapor pressure. Compounds such as polycyclic aromatic hydrocarbons, which have a low-vapor pressure, cannot be successfully removed by volatilization. Moreover, conventional bioremediation techniques utilizing indigenous microorganisms alone or in combination with genetically altered exogenous microorganisms is not always effective for degrading certain types of recalcitrant contaminants which are strongly resistant to biodegradation. Genetically engineering microbes is also time consuming and expensive and may result in a strain that is capable of achieving a desired metabolic function, but is weakened in other key metabolic areas, resulting in a strain that is ineffective or cost-prohibitive in large-scale production and use.
In addition, many of the present techniques for remediating soils and water take long periods of time to reduce the contaminants to acceptable or non-detectable limits. Faster treatment times of larger contaminated areas or volumes is a long-standing need in industry, that has the potential to reduce the cost of bioremediation, as well as the lost opportunity costs of land and resources that cannot be used due their contaminated state.
Thus, while various known techniques are available for the disposal or reclamation of contaminated soil, such methods do not generally provide a practical, affordable technology for remediating soil and water sources in reasonable periods of time. Accordingly, there is a need for simple, inexpensive, environmentally acceptable methods and means for remediating soils and water, within time spans on the order of days, instead of many months or even years.